1. Field of the Invention
The present invention relates to a motive power generating apparatus utilizing magnetic energy of permanent magnet, specifically to a motive power generating apparatus providing higher energy conversion efficiency than those of the conventional electric motors.
2. Description of the Related Art
Various types of electric motors have been conventionally developed, which are designed to convert electric energy into mechanical force such as torque. What is common among those general electric motors is that electromagnets are employed as either stators or rotors, to which electric current is supplied from an external system. For example, in a typical induction motor configuration, a rotating magnetic field is generated by sequential change of a current supply to a plurality of electromagnets disposed in the stator and a rotor of a shape such as a squirrel cage follows the rotating magnetic field to produce an output torque. A typical dc motor includes a rotor rotatably arranged in a magnetic field of permanent magnets as a stator. The rotor is designed so as to change its polarity to produce torque by magnetic force between magnetic fluxes of the rotor and the stator.
Various attempts have been made in improving an efficiency of such conventional electric motors by utilizing magnetic flux from a permanent magnet. The present inventor has specifically focused on appropriate control of magnetic flux from a permanent magnet. Through experiments by experimental motors of various types using such appropriate control of magnetic flux distribution, the present inventor has confirmed that the control of magnetic flux distribution can successfully reduce magnetic force applied to the rotor, which prevents the rotor from rotating, and improves efficiency in converting electromagnetic energy to kinetic energy. Among the experimental power generating apparatuses is a motive power generating apparatus disclosed in Japanese Laid-open Patent Publication No. 7-7907 filed by the present inventor. The apparatus includes a rotor having a permanent magnet to improve conversion efficiency.
Recently, it has gradually become obscure if resources of energy such as fossil energy will be supplied constantly in future. At the same time, environmental problems such as an air pollution and a greenhouse effect emerge as an urgent agenda. Due to those conditions, it is strongly demanded to develop a motive power generating apparatus which enables conversion of electric energy into kinetic energy as efficiently as possible.